OpenMusic is based on the Common Lisp programming language. Creating an executable in Common Lisp means loading all the source code in the Lisp environment and build an "image" of it, i.e. another Lisp environment extended with the features defined in the code.
It is also possible to compile and load OM source code in the Lisp environment and use it directly without saving a new image. Using OM sources therefore requires owning a Lisp compiler.

OM 6 is developed with LispWorks (5.1/6.0/6.1) and relies on the graphical and GUI toolkits provided by this commercial Lisp environment. A free (limited) edition is also available on the LispWorks website.

The current OM sources can be compiled and run OM on MacOS X, Windows and Linux (see compilation instructions below).

The LispWorks Personal Edition has a limited heap size, which might be exceeded just by compiling the full OM sources. In this case, LispWorks will quit without finishing the compilation, but next time part of the code will already be compiled. After two or three times, the OM code is compiled and OM can be run as in LispWorks Pro (but still with a limited heap size).

A solution to limit the heap occupied by OM is not to load all the OM projects and components.

The "projects" are specific thematic packages included in the OM base distribution.
When compiling OM, you can decide to include or not the different OM projects.
In the build-om.lisp file, you will find lines staring with (load-om-projects …) that can be commented if you don't want to load some specific projects project. This might sensibly reduce the memory and heap size consumption of OM.

LispWorks Personal has also a time limit of 5 hours for each session, after which it will exit as well (but still can be restarted).

If you download and install the OM packaged application instead of the basic source archive, all fonts and dependencies will be installed automatically (and you can skip the corresponding sections on this page).

kernel : In the OM kernel is implemented the core visual programming environment. Classes and methods for the language meta-objects are defined (i.e. OMPatch, OMClass, OMBox, etc.), as well as their representations either as simple icons or as container. Meta-objects for the OM environment (OMFolder, OMWorkspace, OMLib, etc.) are also defined with graphic manipulations for creating or modifying them. Default graphic control structures as omloop, omif, or logic predicates and tools are also predefined in the OM kernel.

projects : Each "project" is a specialized set of classes and methods that can be accessible and visualisable in the OM environment.

buildimage : Contains the files and resources needed to build the image of OM.
This folder is also divided in sub-folders corresponding to the different available platforms.

patches : Any file in this folder is loaded at OM startup. We provide minor revisions between releases in order to add bug corrections or code. OM users can put these 'patches' in this folder.

OM API Reference: A cross-platform interface for UI and Lisp implementation specific features.
The OM API specification defines a set of functions and classes related to the graphical and platform-dependent part of the OpenMusic code.